// MIT License

// Copyright (c) 2019 Erin Catto

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#include "test.h"

class ConveyorBelt : public Test
{
public:
    ConveyorBelt()
    {
        // Ground
        {
            b2BodyDef bd;
            b2Body* ground = m_world->CreateBody(&bd);

            b2EdgeShape shape;
            shape.SetTwoSided(b2Vec2(-20.0f, 0.0f), b2Vec2(20.0f, 0.0f));
            ground->CreateFixture(&shape, 0.0f);
        }

        // Platform
        {
            b2BodyDef bd;
            bd.position.Set(-5.0f, 5.0f);
            b2Body* body = m_world->CreateBody(&bd);

            b2PolygonShape shape;
            shape.SetAsBox(10.0f, 0.5f);

            b2FixtureDef fd;
            fd.shape    = &shape;
            fd.friction = 0.8f;
            m_platform  = body->CreateFixture(&fd);
        }

        // Boxes
        for (int32 i = 0; i < 5; ++i)
        {
            b2BodyDef bd;
            bd.type = b2_dynamicBody;
            bd.position.Set(-10.0f + 2.0f * i, 7.0f);
            b2Body* body = m_world->CreateBody(&bd);

            b2PolygonShape shape;
            shape.SetAsBox(0.5f, 0.5f);
            body->CreateFixture(&shape, 20.0f);
        }
    }

    void PreSolve(b2Contact* contact, const b2Manifold* oldManifold) override
    {
        Test::PreSolve(contact, oldManifold);

        b2Fixture* fixtureA = contact->GetFixtureA();
        b2Fixture* fixtureB = contact->GetFixtureB();

        if (fixtureA == m_platform)
        {
            contact->SetTangentSpeed(5.0f);
        }

        if (fixtureB == m_platform)
        {
            contact->SetTangentSpeed(-5.0f);
        }
    }

    void Step(Settings& settings) override { Test::Step(settings); }

    static Test* Create() { return new ConveyorBelt; }

    b2Fixture* m_platform;
};

static int testIndex = RegisterTest("Examples", "Conveyor Belt", ConveyorBelt::Create);
